Theodore W. Selby in U.S. patent application Ser. No. 08/425,587 filed Apr. 20, 1995, which is incorporated herein by reference and which is now U.S. Pat. No. 5,526,681 (Jun. 18, 1996), has disclosed a gas-containing vessel to establish desired heat flux. Such a vessel, i.e., one useful for heat transmission regulation comprising a sealable, hollow housing about a sample compartment wherein a hollow portion of the housing contains a predetermined amount of a gas, and method to employ it in viscosity testing, e.g., in an improvement of the ASTM D 2983 protocol, are significant improvements in the art.
Nevertheless, room exists for further improvements.